High wear resistance, low temperature property, flame resistance, and others are demanded for wires and cables applied to railway vehicle, automobile, and equipment, etc., as needed.
It has been known that a polymer with high crystallinity (such as HDPE) is basically used in order to obtain high wear resistance. However, since the polymer has low filler receptivity, a halogen-based flame retardant or a phosphorus-based flame retardant such as red phosphorus, which has the effect for the flame resistance with a small amount of addition, has to be used.
However, since the halogen-based flame retardant generates halogen gas at the time of combustion, there is a lack of consideration for environmental problems that has been increasingly demanded worldwide. Moreover, the phosphorous-based flame retardant such as red phosphorous also has problems of generating phosphine at the time of combustion and generating phosphate at the time of disposal to pollute underground water vein.
Thus, a non-halogen insulating wire using a metal hydroxide as a flame retardant have been developed (see, for example, Japanese Patent Application Laid-open Publication No. 2013-214487 (Patent Document 1).